Apparatus for the binding of stacked sheets



APPARATUS FOR THE BINDING 0F STACKE D SHEETS Filed April 25, 1967 Sept.29, 1970 osT ETAL 5 Sheets-Sheet l THERMALLY l OWABLE ADHESIVE Atfomc yAPPARATUS FOR THE BINDING OF STACKED SHEETS Filed April 25, 1967 Sept.29, 1970 H. ROST ETAL 3 Sheets-Sheet 2 INVENTOR.

Sept. 29, 1970 H. ROST ETAL 3,531,358

APPARATUS FOR THE BINDING OF STACKED SHEETS- Filed April 25, 1967 sShects-5heei 5 BY {Kari Attorney INVENTOR.

United States Patent Int. (:1. B29c 24/00 U.S. Cl. 156-475 12 ClaimsABSTRACT OF THE DISCLOSURE Apparatus for the adhesive binding of stacksof sheets or leaves whereby the stack is jogged with an edge against asupporting plate and the plate is heated and withdrawn from the stackwhich is held in a clamp while a foil of thermally fiowable solidadhesive is placed between the hot plate and the juxtaposed edge of thestack in the form of a slip fold, the latter being then bonded to theedge and around the cover and backing sheets of the stack between splitsections of the heated plate. The slip fold comprises a reinforcing webof paper, gauze cellulose hydrate as a backing layer coated by thethermally sensitive adhesive or a reinforcing web embedded therein.

The invention relates to an apparatus for the threadless binding ofpiles of sheets in which a solid adhesive free from solvent (meltableadhesive) is used which is reduced to a fluid state and renderedadhesive by the action of heat.

Piles of sheets are generally treated with a liquid adhesive and thenallowed to set. The piles of sheets thus treated are, however, not readyfor use until the adhesive has set, depending upon the time required bythe solvent to evaporate.

In order substantially to reduce the setting time, it is known to useso-called meltable adhesives (hot melt) which form a solid mass sincethey contain no liquid solvent of any kind. This mass is reduced to afluid state and becomes adhesive when it is heated.

It is known to reduce meltable adhesives of this kind to a fluid stateby heating them in a container, and to 4 apply the hot adhesive to theworkpiece by mechanical means, for example by dipping or immersionplates. Apart from the substantial amount of energy required, particulardifficulties are caused by the long heating-up periods having to beallowed for before the work is started, the constant presence of air inthe zone of adhesive application involving the danger of oxidation, andthe loss of time due to starting and stopping of the machine withresultant variation of the conditions under which the meltable adhesiveis applied. Particular disadvantages arise from the fact that largequantities of the meltable adhesive have to be heated up, whereas onlysmall portions thereof can be treated at a time.

It is the object of the invention to avoid these diffi culties and todevelop a cheap and, at the same time, time-saving binding method inwhich meltable adhesives are used.

In accordance with the invention, the solid adhesive applied in the formof a foil to the back of the pile of sheets or leaves is heatedsubsequently to its application.

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This affords the advantage that only a small portion of the adhesive hasto be heated at a time, so that a substantial amount of energy and timeis saved, and the meltable adhesive is not subjected to excessivethermal stresses.

Within the framework of the invention it has been found to beadvantageous for a support coated with the solid adhesive to be appliedto the back of the pile of sheets or leaves and then to be heated. Inaccordance with the invention, a slip-fold or the like consistingpreferably of a strip of paper, gauze, cellulose hydrate or equivalentmaterial may be used. In accordance with the invention, the layer ofadhesive to be applied to the back of the pile of sheets or leaves mayalso be provided with at least one layer of gauze, fiber, or a fleecymaterial.

The apparatus according to the invention comprises a clamping device, bywhich the pile of sheets or leaves is held in position, and, extendingat right angles thereto, adjacent thereto or at a distance therefrom, ajogging face contacted by the sheet edges to be glued together.

In accordance with the invention, the jogging surface forms part of adirectly or indirectly heated hot plate disposed at an adjustabledistance from the clamping device to enable a support in the form of astrip coated with meltable adhesive to be introduced.

The apparatus affords the advantage that the pile of sheets may bejogged directly on the hot plate and then clamped in position so thatthe back of the pile of sheets assumes an exactly determined positionrelative to the hot plate. The support is applied to the spine of thepile of leaves under a suflicient pressure when the hot plate is moved aslight distance away from the spine of the pile in order to enable thesupport coated with the meltable adhesive to be introduced into the gapthus formed, and when the hot plate is subsequently returned to itsoriginal position. The hot plate has to be preheated for a predeterminedperiod previously and then has to remain constantly heated so that theadhesive reduced by the hot plate to the fluid state glues the edges ofthe sheets securely together to form a secure bond within a minimumperiod of time. The single heating-up of the hot plate requires muchless energy and time than the conventional heating of the meltableadhesive in a bath.

In accordance with the invention furthermore, the hot plate may be of abipartite or multipartite construction, each component part beingadapted to move at right angles to the jogging surface. It isadvantageous for at least the larger section of a bipartite hot plate tobe adapted to move parallel as well as at right angles to the joggingsurface. It has also been found to be advantageous for the abutting endof the bipartite hot plate to be disposed in substantially the sameplane as the contact surface of one of the clamping elements of theclamping device.

The bipartite or multipartite construction of the hot plate affords theadvantage that a slip fold may serve as a support for the meltableadhesive to glue the back of the pile of sheets; in addition, itsperipheral zones are folded around the back of the pile of sheets andglued to the cover and base sheets of the pile in the manner usual inslip-folding operations. The multipartite construction of the hot plateenables the abutting ends thereof to be used not only for folding backto the peripheral zones of the slip fold, but also for pressing orrubbing it against the cover and base sheets of the pile. The fact thatthese abutting ends of the hot plate are also adapted to be heatedresults not only in the mechanical phase of the movement hereinbeforedescribed, but also in a more expeditious liquefaction of the meltableadhesive in the folded-over state.

In accordance with the invention, furthermore, the hot plates areadvantageously mounted on a vertically ad- 3 justable trestle andconnected to a cam or eccentric drive. It has been found particularlyadvantageous to provide a control shaft, preferably of a manuallyoperable construction, secured to the driving means by which thesections of the hot plate are lifted and moved apart so that themovements proceed in the correct order of succession in the manner of afollower or sequential control, as the control shaft is turned.

In one construction according to the invention, a feed bar needled withspikes or the like for advancing the support of the meltable adhesive isprovided which moves substantially in the plane of the jogging surface.In accordance with the invention, the support has previously been cut tothe correct measurement, so that there is merely the problem of movingthe support to the correct position below the back of the pile of sheetswithout damaging the adhesive coating and without the succession ofmovements being disturbed by the layer of adhesive. It will beunderstood that it is within the scope of the invention to feed thesupport directly from the roll, which is then cut to the correct lengthin the zone of the binding machine.

Details of the invention are diagrammatically illustrated by way ofexample in the accompanying drawing in which:

FIG. 1 is a longitudinal sectional elevation of a threadless-bindingmachine; and

FIGS. 2 to 9 show corresponding longitudinal sections through thethreadless-binding machine in various phases of movement.

The construction according to the invention illustrated in FIG. 1comprises a manually operated machine for the threadless binding ofpiles of sheets or leaves 1, of whose edges 2 to be glued are to becontacted with a support 3 which is coated with a layer of meltableadhesive. In the construction illustrated by way of example in thedrawing, it is assumed that the support 3 has previously been cut to thecorrect size externally of the threadless-binding machine. The support 3is moved to the zone of the sheet edges 2 to be glued by a feed bar 4needled with spikes 5. The preferred support used for the glueingoperation is a slip fold which is effective to bring about an adhesivebond under the edges of the sheets, to glue the back of the pile ofsheets, and, finally, to glue the cover and base sheets of the pile inthe peripheral zone.

In the construction illustrated by way of example in FIG. 1, the pile ofsheets 1 is clamped in position by a bipartite clamp 6 provided at adistance from the jogging surface 8. The jogging surface 8 constitutessimultaneously a major part of a hot plate 9 which consists preferablyof two hotplate sections 11 and 12. The vertical junction betweenabutting contact edges 10', 10" (FIGS. 5 and 6) of the two hotplatesections 11, 12 is disposed substantially in the same plane as thecontact surface 7 of one of the clamping elements 6. The hotplate 9 maybe heated directly. In the illustrated embodiment, the heating elemerits(not shown) are disposed in a table top 20, so that the hotplate 9 isheated indirectly, during which process the two plates 9 and shouldcontact each other directly.

In FIG. 1, the hotplate 9 is mounted on a trestle or brace 14 which ismoved by guide rods 15 in bearings 13 at right angles to the joggingsurface 8, so that the jogging surface 8 may be moved toward and awayfrom the sheet edges 2 to be glued. The trestle 14 is driven by aneccentric 16 which may be operated by a crank or the like.

The individual operations required to produce the adhesive bond in theillustrated embodiment are shown in FIGS. 2 to 8.

FIG. 1 shows the apparatus according to the invention with the hotplate9 in its normal position, the clamping device 6 being released to enablethe pile of sheets 1 to be leveled on the jogging surface 8 of thatplate. The clamping device is then operated, and the pile of sheets 1 isthus clamped in position so that the sheet edges 2 to be glued come torest exactly on the jogging surface 8. The hotplate 9 is then heated forabout 20 minutes, the heating being preferably continued throughout theoperating cycle. In the initial phase illustrated in FIG. 1, themeltable adhesive on the support 3 is still in the solid state, beingheld separated from the hotplate assembly 9, 20.

It is now necessary for the support 3 to be moved into the gap betweenthe pile of sheets 1 and the hotplate 9. For this reason, the eccentricor cam 16 (FIG. 2) is turned until the hotplate 9 together with thetrestle 14 descends. The support 3 is then introduced by feed bar 4 intothe gap formed between the sheet edges 2 and the jogging face 8;conventional markings or other auxiliary means may be used for thispurpose in order to adjust the correct position of the support 3. Duringoperation, the movement of the feed bar 4 is advantageously geared tothe movement of the trestle 14. This may advantageously be achieved, forexample, by means of a crank drive starting from the shaft of theeccentric 16. As best seen in FIG. 3, the width of the support 3 exceedsthe width of the pile of sheets 1. As previously mentioned, a slip foldis used by which. not only the back of the pile of sheets but also theperipheral zones of the cover and base sheets are glued. In thesubsequent operations, the feed bar 4 may remain in the illustratedposition since it does not interfere with the process.

Whereas FIG. 3 shows the slip fold-type support 3 spaced from theunderside of the pile of sheets 1, FIG. 4 shows the eccentric as it isreturned to its original position, so that the hotplate 9 together withthe support 3 resting thereon may be pressed against the sheet edges 2of the pile 1 to be glued. The plate 9 may then be heated if this hasnot been carried out previously. The solid meltable adhesive is thusreduced to the thermoplastic state, the flowing adhesive beingdistributed between the sheet edges so as to create the necessaryconditions for a perfect adhesive bond.

FIGS. 5 to 8 illustrate the completion of the adhesive bond by the useof the slip fold 3, and the folding operation. In FIG. 5, the largersection 12 of the hotplate is moved to the right until its contact edge10" has reached a position substantially in the plane of the right-handface of the pile of sheets 1, a recess being thus formed below the sheetedges 2 to be glued.

A lifting cam 19, larger than eccentric 16, on a control shaft 17 isthen rotated to raise the trestle 14 and the hot plate 9 to an extentsutficient to ensure that the exposed edges of the slip fold 3 are bentback as illustrated in FIG. 6 and can be pressed against the cover andbase sheets of the pile of sheets 1 as illustrated in FIG. 7. The edges18 of the support or slip fold 3 are then bent up pressed against thestack 1 and heated by the contact edges 10, 10" of the hot-platesections 11, 12. It will be noted that the adhesive bond and the foldingproceed in one operation. When the position illustrated in FIG. 7 hasbeen maintained for a predetermined period of time until the settingprocess is complete, the hot plate 9 and the trestle 14 are lowered totheir initial position and the hotplate sections 11, 12 aresimultaneously re-joined. The clamping device 6 can then be released andthe glued and folded pile of sheets 1 can be Withdrawn without the riskof the adhesive bond being disturbed, since the meltable adhesive setswithin a short time. Even when the heating elements are dispersed in thetable top 20, the meltable adhesive is adequately heated in the zone ofthe contact edges 10, 10" owing to the increased heating area which iseffective when the hot-plate sections 11, 12 have been moved apart.

It will be understood that it is advantageous for the control shaft 17to be connected to the driving means required for lifting and moving thehot-plate sections 11, 12 apart. The compressive motion illustrated inFIG. 7 can be carried out by the same apparatus so that, as the controlshaft 17 rotates through a predetermined angle, all the necessaryoperations may proceed in the correct order of succession without theoccurrence of errors. The eccentrics 16 and 19 are advantageouslysecured to different shafts.

FIG. 9 shows by way of example the manner in which the control shaft 17can be used both for pulling the hotplate sections 11, 12 apart and forlifting the work table 14. Connected to a crank pin 21 by a link 22 is arocker arm 23 which drives the hot-plate section 12 by means of a guidelever 24. The control shaft 17 has thus only to be turned through acertain angle to carry out the necessary operational steps in thecorrect order of succession.

A piece of film of meltable adhesive corresponding to the measurement ofthe spine of the book is cut off, placed on the jogged, cut stack, andpressed slightly against it with simultaneous heating. The adhesivelayer melts at a temperature upward of 80", more specifically atemperature of 100, to such an extent as to form a satisfactory bondwith the edges of the individual sheets. The bond sets upon cooling.

In the simplest case, it is sufiicient to use a smoothing iron for thisoperation. Inexpensive tools may be used even for series production. Thefilm of meltable adhesive may be used in the form of an unsupportedfoil, or it may be applied to a backing according to the requirements ofthe processing plant.

The unsupported material will be preferred when the stack bonded withadhesive is to be cased or inserted as a pamphlet, since the cover canthen also be glued in position by slight re-heating.

For purposes of this kind, even more durable layers may be obtained byembedding a gauze or a fleecy material in the meltable adhesive, e.g.when the stack is to be processed as a book. When the stack is to befolded, a meltable adhesive supported by a binding or folding material,such as paper, linen or the like, is advantageously used, so that thebinding and folding steps are carried out in one operation.

The thermally flowable adhesive referred to above is conventional in theart of bookbinding; see, for example, US. Pat. Nos. 1,858,685 (RubberIsomers), 2,579,488

(Polyvinyl Chloride) or 3,223,436 (Polyethylene).

Finally, a support consisting of a foil of cellulose hydrate may be usedwhich, during the folding operation, produces a high-gloss spine whichmay, however, be removed if required, after having been moistened withwater, e.g. when the film of meltable adhesive is still to be used forglueing the book into a cover. The films of supported or unsupportedmeltable adhesive are produced by casting from the melt, e.g. by meansof a heated spreading tool in a conventional coating machine in whichthe drying channel can be utilized for cooling but may also be dispensedwith.

It will be understood that the embodiment illustrated by way of examplein the drawings may be modified in many ways, as by providing a fullyautomatic threadlessbinding machine of a similar construction.

We claim:

1. An apparatus for binding a stack of sheets, comprising:

jogging means including a plate with a generally flat surface adapted toalign a stack of sheets, extending perpendicularly to said surface,along at least one edge of the stack;

clamping means engageable with said stack for retaining said sheets inan aligned condition and supporting said stack independently of saidplate;

heating means for said plate;

reversible shifting means for relatively displacing said clamping meansand said plate to form a gap between said surface and said edge of thestack engaged by said clamping means;

and mechanism for inserting into said gap a strip of a thermallyflowable adhesive adapted to be bonded to said sheets along said edge atthe temperature of said plate upon subsequent relative reversedisplacement of said plate and said clamping means.

2. The apparatus defined in claim 1 wherein said surface is horizontal,said shifting means comprising a ver tically reciprocable brace carryingsaid plate and an eccentric drive engageable with said brace for raisingand lowering said plate relatively to said clamping means.

3. The apparatus defined in claim 1 wherein said plate is split into twonormally contiguous sections separable, upon formation of said gap bythe operation of said shifting means, to define between them a recessregistering with said edge, said recess having boundaries flanking saidstack for pressing bentover marginal portions of said strip against theouter sheets of said stack upon reverse opera tion of said shiftingmeans to introduce part of said stack into said recess.

4. The apparatus defined in claim 3 wherein said shifting meanscomprises first camming means for defining a. normal relative positionof said plate and said clamping means in which said stack bears uponsaid surface with said sections contacting each other, prior toformation of said gap, said shifting means further comprising secondcamming means for relatively displacing said plate and said clampingmeans toward each other beyond said normal position with said sectionsspaced apart to introduce said part of said stack into said recess.

5. The apparatus defined in claim 4 wherein one of said sections isstationary and forms with a contact edge of the other section in theircontiguous position a junction substantially in the plane of one face ofsaid stack, further comprising separating means operable in timedrelationship with said shifting means for moving said other section intoa spaced-apart position in which said contact edge lies substantially inthe plane of the other face of said stack.

6. The apparatus defined in claim 5 wherein said surface is horizontal,further comprising a table supporting said sections while beingvertically movable by said shifting means, said other of said sectionsbeing slidable on said table.

7. The apparatus defined in claim 1, further comprising a table carryingsaid plate, said heating means being provided in said table.

8. The apparatus defined in claim 1 wherein said mechanism includes afeed bar provided with a plurality of spikes and shiftable in a planeparallel to said surface for advancing the strip.

9. An apparatus for binding a stack of sheets, comprising:

a plate split into two normally contiguous sections with a continuoussurface adapted to align a stack of sheets, extending perpendicularly tosaid surface, along at least one edge of the stack, said sections beingseparable to define between them a recess registering with said edge;

clamping means engageable with said stack for retaining said sheets inan aligned condition and supporting said stack independently of saidplate, said clamping means being movable relatively to said plate toform between said edge and said surface a gap for the insertion of astrip of a thermally flowable adhesive in the contiguous position ofsaid sections;

and heating means for said plates to bond said strip onto said edge andonto the outer sheets of said stack upon introduction of part of saidstack together with said strip into the recess formed by the separatedsections.

10. An apparatus for binding a stack of sheets, com prising:

jogging means including a plate with a generally fiat surface adapted toalign a stack of sheets, extending perpendicularly to said surface,along at least one edge of the stack;

clamping means engageable with said stack for retain- 7 ing said sheetsin an aligned condition and supporting said stack independently of saidplate, said clamping means being movable relatively to said plate toform a gap between said edge and said surface; heating means for saidplate;

and mechanism for inserting into said gap a strip of a thermallyflowable adhesive adapted to be bonded to said sheets along said edge atthe temperature of said plate, said mechanism including a feed barprovided with spikes and shiftable in a plane parallel to said surfacefor advancing said strip.

11. An apparatus for binding a stack of sheets, comprising:

a table provided with heating means;

a plate disposed on said table in heat-transfer relationship therewith,said plate having a generally flat surface;

jogging means including said plate for aligning a stack of sheets,extending perpendicularly to said surface, along at least one edge ofsaid plate;

clamping means engageable with said stack for retaining said sheets inan aligned condition and support- 8. ing said stack independently ofsaid plate, said clamping means being movable relatively to said plateto form a gap between said edge and said surface;

and mechanism for inserting into said gap a strip of a thermallyflowable adhesive adapted to be bonded to said sheets along said edge atthe temperature of said plate.

12. The apparatus defined in claim 11 wherein said jogging meansincludes means for shifting said plate perpendicularly to the joggingsurface thereof.

References Cited UNITED STATES PATENTS 3,223,436 12/1965 Becker 281-21XR 2,968,336 1/1961 Martin et a1. 1,858,685 5/1932 Semon 28121 2,579,48812/1951 Freeman 28121 PHlLIP DIER, Primary Examiner US. Cl. X.R.

